Ok, so now I'm on the hunt for a telephoto lens so I'm doing searches on ebay, froogle and what not but what copletely confuses me are the abbrevations included in the lense's names. What I want is basically the Sigma 70-200mm 2.8 (important) APO for a Nikon D50. I don't even know what the APO means but I've heard it's important. Difefrences I've noticed: There's apparently a Macro lens and a non-macro lens, correct? Some have 'DG' included in their name, what does it mean and what's wrong with the lenses that don't have 'DG'? What about EX and HSM? I found a dozen lenses on ebay that seem right but all have varying names, meaning varying abbrevations, and I have no idea anymore. I'd like to get the macro one but that's not mandatory, what's most important to me is the long focal length combined with the 2.8 f-number. HELP! :blushing: Thanks!